A method of humidity control, referred to as humidistatically controlled heating, is described. This method of control operates on the principle that the relative humidity of a constant volume of air with a given moisture content can be controlled by changing the temperature. The theory of operation and method of implementation are described. The results of a field test indicate that this method can be successfully used for the relative humidity control of uninhabited buildings during the winter months. See AATA 9-55 and 21-1279 for related studies.